Sewing machine



F. LUTZ SEWING MACHINE June 24, 1958 4 Sheets-Sheet 1 Filed Feb. 17, 1954 WWW/[1111M June 24, 1958 F. LUTZ SEWING MACHINE 4 Sheets-Sheet 2 Filed Feb. 17, 1954 XIII [E S g $7 IL u m/ I M v. m U

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F. LUTZ SEWING MACHINE June 24, 1958 4 Sheets-Sheet 3 Filed Feb'. 17, 1954 F. LUTZ SEWING MACHINE June 24, 1958 4 Sheets-Sheet 4 Filed Feb. 17, 1954 United States Patent O 2,840,021 SEWENG MACHINE.

Friedrich Lutz, Stuttgart-Degerloch, Germany, assignorto UlllOll Special Maschinenfabrik, G. m. b. H., Stuttgart, Wuerttemberg, Germany Application February 17, 1954, Serial No. 410,871

Claims priority,application Germany March 25, 1953 11 Claims. (Cl. 112-159) This invention relates to a sewing machine, and more particularly to one adapted to produce a two-thread chain stitch along one or more zigzag lines. The machine may be provided with a single needle and single looper, or a plurality of needles and a corresponding plurality of loopers. Each of the stitch forming instrumentalities is provided with thread so'that either a single line or a plurality of lines of two-thread chain stitches may be produced in zigzag fashion;

If the machine is provided with a single needle and a single looper it is primarily useful in forming an ornamental scalloped effect along the edge of a piece of work advanced through the machine. The zigzag line of stitches formed in the course of advancing the work is attached to the edge of the work at periodic intervals. Any desired number of stitches may be provided between the points at which certain of the stitches are attached to the work. In a typical machine, of the character to be more fully described, the arrangement is such that every sixth stitch becomes attached to the work and the intervening sitches project, to a successively greater extent and then a diminishing extent, from the edge of the work to provide a scalloped effect.

A machine provided with a plurality of thread carrying needles and a corresponding plurality of thread carrying loopers may be similarly used to provide an ornamental effect along the edge of a piece of work advanced through the machine. The arrangement is then preferably such that one of the zigzag lines of stitches becomes attached to the edge of the work at periodic intervals as, for example, at exery sixth stitch, while the other line of zigzag stitches crosses or overlaps the first line of stitches at points where the latter project to the greatest extent from the edge of the work, and the two lines of stitches are interconnected at these points of crossing or overlapping.

Either of the foregoing types of machine may also be utilized to provide an ornamental seam between two edges of work which are advanced in slightly spaced, but parallel relation through the stitch forming zone of the machine. When a single needle and single looper are provided, the stitches at periodic intervals, say every sixth one, will be passed through one of the edges of the work while other stitches at periodic intervals, say the third, ninth, etc., will be passed through the other of the spaced edges of the work. If a plurality of needles and loopers are provided, one of the zigzag lines of stitching may be attached at periodic intervals to one of the free edges of the work while the other line of zigzag sitches may be attached at periodic intervals to the other free edge of the work, and the two lines of stitches will cross or overlap and become interengaged and interlocked at corresponding but intermediate intervals. A variety of other ornamental effects may be produced in accordance with the invention.

To provide one or more zigzag lines of stitching in the manner explained, the machine embodies a needle bar which is reciprocated vertically for the formation of stitches and is also shifted laterally in successive steps Patented June 24,1958

in directions transverse to the line of feed, firstly a number of steps in one direction and then the same number of steps in the opposite direction, to provide the zigzag effect. The cooperating looper is given three types of movement. It is oscillated about a pivot point to provide the loop seizing and loop shedding functions, in a direction transverse to the line of feed. The looper carrier is also shifted back and fourth in the line of feed, prof erably by a rocking movement, to impart needle avoid movements to the looper. To insure proper coordination between the needle and the looper and the production of uniform stitches, the looper is also shifted bodily, in a. direction transverse to the line of feed, in coordination with the transverse movements of'the needle bar and needle in producing the zigzag stitch effect. When a plurality of needles and a plurality of loopers are employed, these partake simultaneously of the same movements as the single needle and the single looper described above.

Machines as heretofore constructed for the purpoes of providing zigzag lines of stitching, to produce ornamental effects and the like, have been of relatively bulky and complicated construction and have involved operating devices and connections projecting in various directions from the main frame of the machine. These machines have not been capable of high speed operation. Their maximum speed of operation has normally been about 2,200 R. P. M., due to difliculties encountered at higher speeds of operation.

A primary purpose of the present invention has been to provide a sewing machine, capable of providing one or more lines of sitching of the character indicated, which is of simple and lightweight construction, compact, economical to produce, and capable of high speed operation;

Another object of the invention has been to provide a construction, of the character indicated, in which the various operating devices for imparting all of the. necessary movements to the needles and' the loopers are enclosed within the regular frame of the machine.

An important feature of the invention is the provision of means for shifting the needle transversely of the line of feed to provide the. zigzag effect, and'the corresponding bodily movement of the looper, by operating parts which are disposed substantially in a common vertical plane transverse to the line of feed of the machine. This feature enables the provision of parts which have a minimum movement for imparting the transverse shifting motionsto the needle and looper to bring about zigzag stitch forma tion. The operating parts may be made of relatively lightweight construction, and the arrangement is such that the driving connections will never become locked as they sometimes do with the constructions of the prior'a'rt. They also occupy a relatively small amount of space and may readily be housed within the enclosure provided by the regular hollow frame of the machine.

Another important feature of the invention is the provision of a simple, relatively light and small face cam of disk like form for operating the mechanism which shifts the needle bar and the needle step by step transverselyof the line of feed. In the preferred construction this cam is disposed horizontally and is rotated about a verti cal axis. It has upwardlyand downwardly extending pro-- iections on its opposite faces which are complementary; and cooperate with a pair of spaced rollers mounted 01ia rock frame forming part of the mechanism for shifting the needle bar transversely. The projections serve-to shift the rock frame, and hence the needle bar, step bw step with a dwell between successive steps of movement. Little space is required to accommodate the facecarn; and it operates positively and with little noise at'high" speeds. '2

Another feature of the invention is the provision of a: separate control for the bodily movement of the looper or loopers in coordinated relation with the transverse 'the top of the shaft, while the eccentric is disposed adjacent its lower end. It has been found that while it is necessary to shift the needle step by step in.the direction transverse to the line of feed, so that it will not be shifted during the intervals in which the needle penetrates the work, it is not necessary toprovide such step by step bodily movement of the-looper or loopers. These may be maintained in proper relation to the needle or.

needles even though the controlling eccentric serves to shift the looper carrier bodily in thetransverse direction substantially continuously. This bodily shifting of the looper carrier is small during any period in which the needle is in the region of the looper. By proper coordination between the face cam which shifts the needle bar and the eccentric which bodily shifts the looper or loopers, correct stitch formation is assured at all times.

A further feature of the invention is the provision of a simple worm and worm gear connection between the main drive shaft of the machine and the vertically disposed control shaft which carries and operates the face cam and the eccentric described above. This worm and worm gear drive is such as to provide the desired number of stitches between the intervals at which the stitches are connected with the work. Thus, if a scallop is to be formed of six stitches, the gearing is such that six revolutions of the main drive shaft will impart only one revolution to the control shaft. Obviously if a greater or smaller number of stitches is desired for each scallop, the ratio may be varied accordingly by substituting a different worm and worm gear combination. At the same time the face cam for imparting the transverse shifting movements to the needle bar should be changed to provide a corresponding number of progressivelyascending and descending face projections, with intermediate, substantially flat surfaces to provide dwells. &

Still another feature of the invention is the provision of adjustable connections between the face cam on the control shaft and a rock frame which carries the needle bar, these connections being such that the extent of rocking movement imparted to the needle bar in the course of operation of the face cam may be varied as desired. If substantial variation is made in the extent of swinging movement of the needle bar frame, a corresponding variation in the extent of bodily movement of the looper carrier should also be made. This may be accomplished by selection of an appropriate eccentric for imparting the bodily movements to the looper carrier.

Another feature of the invention, is the employment of a hollow control shaft which extends upwardly from a lubricant reservoir at the base of the vertical standard of the machine and is provided at its lower end with a suitable lubricant pump, preferably -by forming a' spiral groove in the outer surface of the shaft in the region which cooperates with the lower bearing for the shaft. This pump serves to force oil downwardly along the groove'or grooves and then upwardly through the shaft, the oil being discharged at the upper end of the shaft and flooding the top face of the face cam securedto the shaft. Part of the lubricant so delivered is thrown as a spray and deposited on other wear receiving surfaces within the standard, and at otherpoints within the hollow frame. Some of the lubricant will gravitate back to the reservoir and inthe course of doing so will lubricate the worm and worm gear and other parts adjacent the bottom of the standard. p

A still further feature of the invention is the provision of a zigzag sewing machine of the characterdescribed, .in whichall of the operating parts are disposed within an enclosed housing. The machine is provided with a hollow frame having a work supporting base, avertic'al standard,

'vide the zigzag stitching.

and an overhanging arm projecting over the base from the standard and carrying a needle head at its free end. Provision is made for lubricating automatically the major wear receiving parts of the machine. Communicating with the above mentioned reservoir in the base of the standard is a second reservoir in another enclosed portion of the frame which houses certain eccentrics for imparting loop seizing and shedding movements and needle avoid movements to the looper.

Yet another feature of the invention is the provision of novel connections from an eccentric on the main drive shaft to a pivotally mounted looper carrier for imparting loop seizing and loop shedding movements to the looper or loopers, these connections being of such character that their timing and stroke of operation is substantially unaffected by the bodily movement of the looper carrier in the manner explained above. The connections for this purpose comprise an arm extending laterally from the pivoted looper carrier toward the vertical standard, and an arm extending in the opposite direction from a rock shaft which is rocked by the eccentric that imparts the loop seizing and shedding movements to the loopers. The 'two arms mentioned are disposed substantially horizontally one above the other in substantially the same plane, with the free end of one extending over the free end of the other. A short, substantially vertical link serves to connect the two free ends of these arms.

The invention also encompasses the provision of needle thread guiding and take up means which will not be affected'by changes in the position of the needle bar carrying frame in the course of its rocking movements to pro- A thread take up eyelet is mounted directly on the needle bar and a cooperating thread guide" is mounted on the rock frame which carries the needle bar, thus insuring maintenance of the same relationship between these two guides regardless of the rocking movements of the rock frame. This insures proper control of the needle thread at all times.

Other objects, features, and advantages of the invention will appear from the detailed description of an illustrative form of the invention which will now be given in conjunction with the accompanying drawings, in which Fig. l is a view in longitudinal, vertical section through a sewing machine embodying the invention;

Fig. 2 is a view in horizontal section through the upper portion of the machine taken along the line 22 of Fig. l;

Fig. 3 is a view in horizontal section taken along the line 3--3 of Fig. l, certain parts being sectioned along a lower plane;

.Fig. 4 is a view in vertical section through a portion of the vertical standard of the machine, taken along the line 44 of Fig. l; and Fig. 5 is a view in vertical section through the base of the machine, taken along the line 55 of Fig. l.

The illustrative machine embodying the invention, adapted to provide ornamental zigzag lines of stitching to produce a scalloped edge effect or the like, has an enclosed frame comprising a work supporting base 1, a vertical standard 2 rising from one end of the base, and an overhanging arm 3 extending laterally from the upper end of the standard. At its free end the overhanging arm carries a needle head 4. Extending longitudinally of the base 1, which is divided into a plurality of chambers, two of which are adapted to retain lubricant. is a main drive shaft 5 which is journalled in suitable hearings in the base and extends through the right end wall of the frame (Fig. 1). Outwardly of the frame, the shaft carries a combined handwheel and pulley 6 for driving the machine. It

machine. The stitch forming devices include a vertically reciprocable needle which is driven from a crank 7 having a spherical portion arrange-.1 to cooperate with a strap having corresponding spherical surfaces, this strapbeing carried at the lower end of a pitman 10. The upper end of this pitman also carries a strap having a spherical surface cooperating with a ball pin projecting from the end ofa needle operating lever 9 rockably mounted in the overhanging arm on or with a shaft 8 mounted in the front and rear walls of the overhanging arm. Needle lever 9 extends into the needle head and is there provided with a pivotally connected link 11 which is also pivotally connected with a block secured to a needle bar 12 carryingone or more needles 13 at its lower end. As will be explained, the needle bar 12 is mounted in suitable "bearings, for substantially vertical reciprocation, within a rock frame suitably mounted in the needle head. 'Also vertically disposed within the needle head, and mounted for longitudinal movement therein is a presser. bar 14 carrying a presser foot 15 at its lower end arranged to be urged downwardly, by a suitable spring action on the presser bar in a well known manner, into cooperation with a throat plate 16 or with work passing over the throat plate, to assist in advancing the work. The throat plate 1 6 is suitably carried by a work supporting top 17 of the base 1 of the frame.

Cooperating with the needle or needles beneath the work support is a looper orpair of loopers 18. If a'single needle is provided only a single looper is provided, but if two needles are employed a looper is provided for each needle. The loopers are mounted on a carrier 19 which is formed in two parts, these being releasably connected to permit one part to pivot in relation to the other for the purpose of presenting the loopers in a more accessibleposition for threading and the like. As best shown in Fig. 1, the carrier comprises the two parts 19a and 19b which are pivotally connected by a pivot pin 19c. Normally the parts are held in fixed relation by means of a spring urged sleeve element 20 having a knurled head. This element is carried by a stud secured to the part 19a and is urged inwardly by a spring surrounding the stud within the sleeve. A screw Zita holds the parts in assembled relation. The shank of the sleeve element normally cooperates with an opening in the part 1912 but may 'be disengaged therefrom by an outward pull on the knurled head. At this time the more slender shank of the supporting stud is exposed to the opening in part 1% and may be moved downwardly along the narrow elongated extension 19d of the opening in the part 1%. This permits part 19a to be swung about theflpivot 190 to a suitable extent for the purpose indicated.

Pivotal movements of the carrier member 19 are imparted by a spherical eccentric 21 secured to the drive shaft 5. This eccentric cooperates with a strap 22 of a pitman, the opposite end of which carries another strap cooperating with a ball pin 23 extending into an enclosed lubricant chamber in the base from an arm 24 secured to a rock shaft 25. Toward the front of the machine, and outside of the lubricant chamber, the rock shaft 25 has secured thereto a substantially horizontally disposed arm 26- which extends toward the left (Fig. 1), i. e. toward the vertical plane passing through the line of feed of the work. A link 27 has a strap at its lower end coop crating with a ball pin extending laterally adjacent the outer end of arm 26. The opposite end of link 26 carries a similar strap cooperating with a 'ball' pin extending laterally from an arm 28, which extends substantially horizontally in the opposite direction from the arm 26. and is secured to a sleeve or hub integral with or otherwise connected with the part 1% of the looper carrier 19.

This hub or sleeve is rockably mounted on a stud 3.0. which extends forwardly from a member 31 that is clamped or otherwise secured to a rock shaft 32. This may be adjusted to provide the desired sliding fit between v the blocks 33c, 33d, and the arms 33a, 33b, and the de' siredfit between the opening through the blocks and the outer surface'of the eccentric 34. As best shown inFig. 1

the eccentric 34 is relatively long so as to permit axial movement of the member 33 in relation to the eccentric as the rock shaft 32 is shifted axially in the manner. to be explained.

For the purpose of advancing the work from front to rear along the work supporting surface 17, in timed relation to the stitch forming devices, a suitable feed mecha nism is provided. This preferably is of the four motion feed-dog type and is provided with a differential feed action. The mechanism for this purpose may be of the character disclosed in the patent to Zeier et al., No. 1,884,489 granted October 25, 1932. In the present drawings the mechanism is illustrated in Fig. 3, and comprises afeed dog 35. Since the details of the work feeding mechanism form no part of the novel construction to which this invention is directed, this mechanism need not be described further.

For the purpose of shifting the needle and the looper carrier in coordinated relation in a direction transverse to the line of feed to produce the zigzag line or lines of stitching, and thus provide scalloped edge ornamentation or the like, there is provided a control shaft 36 which is disposed vertically in the standard 2 of the frame. This control shaft is driven from the main shaft 5' by means ofa worm and worm gear connection 37 (Fig. 3). This worm and worm gear drive is so selected as to provide the desired ratio between the revolutions of the mainshaft and the control'shaft, for example, a 1 to 6 ratio. The control shaft is journaled near its upper end in a bearing sleeve carried by an inwardly extending projection 38 on the vertical standard of the frame. control shaft is journaled in a bearing sleeve 39 mounted in the bottom wall of the frame at the base of the ver tical standard. Bearing sleeve 39 extends upwardly into a lubricant reservoir at the bottom of the standard, and the latter is made oil tight to prevent the escape of lubricant which, as will be explained, is dispersed in spray form within the standard. The reservoir at the bottom of the standard communicates through a passage 40 in a wall of the base of the frame with another enclosed chamber 56 into which some of the lubricant'isdelivered' for the lubrication of the eccentrics 21 and 34- and related parts. Certain of these parts are arranged to dip into the lubricant'within the chamber 56 and disperse the same for lubrication of the wear receiving surfaces therein.

The control shaft 35 is hollow and is provided with one or more spiral grooves around its outer surface ad'- jacent its lower end. These grooves cooperate with the bearing surface of the sleeve 39 and are so directed around the shaft that as the shaft 36 is rotated, lubricant will be forced by the spiral groove or grooves toward the lower end of the shaft, into a small pocket provided there, and then upwardly throughthe interior of the shaft to its top. Here the lubricant is discharged over the upper surface of a face cam 41 secured to the shaft 36 adjacent its upper end. Some of the lubricant thus flooded over the face cam will be thrown from the latter as it is rotatedandcreate a lubricant mist or spray adapted to supply lubricant to. the bearing 38 and various other wear receiving surfaces of the parts within the. standard and the overhanging arm. Some. of the. lubricant will also, descend by gravityto the reservoir and in doing so will At its lower end'the serve to, lubricate the worm and worm gear 37' and the crank 7 and other wear receiving surfaces adjacent the bottom of the standard.

The face cam 41 is provided with complementary formations on its upper and lower surfaces which cooperate with a. pairof frusto-conical rollers 42, one above and one below the face cam. These rollers are carried by an ,of. the forked'lever 46 is provided with anupwardly extending arm 47 (Figs. 1 and 2) having an arcuate slot or opening 47a therein. A link 48 is pivotally connected with the arm 47 by means of a bolt 47b which may be adjusted vertically along the arcuate slot or opening 47a and secured in any desired position to effect adjustment .of the movement to be imparted to the needle bar carry- .ing frame by the formations on the cam 41, in the manner to be explained. At its opposite end the link or rod 48 is pivotally connected by a stud 48a with a needle bar carrying frame 49 which is clamped to a rock shaft 50 suitably journaled in the needle head adjacent the bottom of the latter. Through the connections described, rocking movements imparted to the arm 47 by the face cam 41 will be transmitted to the needle bar carrying frame 49 and thus bring about a shifting of the path of the needles 13 in a direction transverse to the line of feed. Arcuate slot or opening 47a is preferably curved along an are having the stud 48a as its center of curvature.

- Face cam 41 is provided on its upper surface with upwardly extending projections inclined at a suitable angle to the horizontal in a circumferential direction, first progressively upward and then progressively downward toward the starting point. Between each adjacent pair of the successive upwardly and downwardly sloping projections thereis provided a fiat, substantially horizontal surface providing a dwell in the operation of the roller 42. It should be understood that the angular disposition of the various surfaces of the cam 41 as described above are in relation to a circumferential direction and that the alternately disposed projections and dwells on the upper face of the cam 41 are suitably inclined in a radial direction to provide a line of engagement with the frustoconical roller 42. On its under face the cam 41 isprovided with complementary downwardly extending projections and intermediate dwell surfaces which are engaged by the lower roller 42. The arrangement is such that the rock member 43,46, 47 will be positively driven in both directions with a minimum of play. If the ornamental stitch to be produced is attached to the work at every sixth stitch, the control shaft 36 is given one revolution for each six revolutions of the main drive shaft 5, and the cam 41 is provided with six successive projections on its upper and lower faces with six intermediate dwell surfaces on each face. The dwell surfaces are so disposed that they will cooperate with the rollers 42 whenever the needles 13 are in cooperation with the work, while the surfaces inclined to the horizontal in a circumferential direction operate on the rollers only when the needles are above the work. The cam projections, therefore, impart their successive increments of movement to the rock frame 49 only when the needles 13 are above the work.

I The rock shaft 50, to which the needle bar carrying frame 49 is clamped, is provided with eccentric journal portions 50a (Fig. l) cooperating with bearings in the front and rear walls of the needle head. The angular position of the shaft in relation to the frame 49 may be varied as desired, andjth en set in adjusted position, by tightening the clamping screw. This arrangement is such that as the rock frame is rocked to shift the needles transversely of the line of feed, the parts will be so positioned as to cause the needles to be carried downwardly through -the openings in the throat plate 16 and between the stitch tongues formed on or carried by the throat plate and will not strike the throat plate as the needles are reciprocated in the stitch forming cycle.

To insure uniform delivery of thread to the needle from the source of supply a thread guide 51 (Figs. 1 and 2) is mounted at the top of the rock frame 49 and partakes of the rocking movements of the latter. A thread take-up arm 52 is secured to the top of the needle bar 12. This arrangement is such that as the rock frame is shifted to produce the zigzag stitch effect the same relationship will always be maintained between the thread guide 51 and the take-up arm 52, thus insuring uniform action on the thread passing under the guide from the source of supply and then through the eyelet in the take-up arm. A removable needle head cover 44 is provided and this, upon removal, gives ready access to the parts within the needle head. A removable cover 3a is also provided at the top of the vertical standard and this, upon removal, gives access'to the cam 41 and related parts. The cam may be readily replaced by a different cam should it be desired to provide a different type of ornamental stitching.

To bring about uniform stitch formation as the needles are swung in a direction transverse to the line of feed, provision is made for imparting a corresponding movement to the loopers 18. This is accomplished from the control shaft 36 which has secured thereto, adjacent its lower end, an eccentric 53. The latter cooperates with a strap carried by a pitrnan 54, the opposite end of which has another strap cooperating with a ball pin 55 extending downwardly from the member 33. It will be apparent that rotation of the shaft 36 will, through the action of the eccentric 53, impart axial movement to the member 33 and the rock shaft 32 to which it is secured. As will be noted, the eccentric 34, with which the member 33 cooperates in the manner described, is of sufficient axial length to permit the desired axial movement of the member 33 to correspond with the swinging movements of the needle bar. Eccentric 53 will not provide any dwells in the axial shifting of the member 33 and rock shaft 32 to correspond with the dwells provided in the cam 41. It has been discovered that no such dwells. are required, since the continuous shifting of the positions of the loopers 18 by the axial movement of rock shaft 32 in the manner explained will serve to maintain the loopers in proper relation to the needles to effect uniform stitch formation. The loopers are not engaged with the work,

and therefore there is no need to provide a dwell in their movement as is necessary with respect to the needles. The slight movement of the loopers during the interval in which the needles are in direct cooperation therewith is not sufficient to interfere with proper stitch formation. By this arrangement a smoother operation of the loopers is brought about and the cam 41 is required to shift only the needles.

While an illustrative embodiment of the invention has been described in some detail, it will be understood that various changes may be made in the construction and arrangement of the several parts without departing from the general principles and scope of the invention as defined by the appended claims. The invention provides a machine capable of operation continuously at a speed of about 4,000 R. P. M. or even higher. There are no driving connections outside of the main hollow frame. Adequate lubrication is provided for all wear receiving parts. The machine operates with a minimum of noise and requires little servicing.

What is claimed is:

l. A sewing machine adapted to provide a zigzag line of stitching which comprises a hollow frame having a work supporting base, a vertical standard and an 'overhanging arm carrying a needle head, a main drive shaft journaled in said frame, means driven by said shaft for said shaft within said hollow frame for reciprocating said needle bar and for swinging'said rock frame, said connections serving to reciprocate said needle bar a plurality of times as said rock frame is swung through one cycle of its swinging movement, a looper in said base cooperating with said needle in the formation of stitches, and connections from said shaft within said hollow frame for imparting loop seizing and shedding movements to said looper upon each revolution of said shaft and for shifting the zone of loop seizing and shedding movements of said looper in coordination with the swinging movements of said rock frame.

2. A sewing machine adapted to provide a zigzag line of stitching which comprises a hollow frame having a work supporting base, a vertical standard and an overhanging arm carrying a needle head, a main drive shaft journaled in said frame, means driven by said shaft for advancing work across said base, a reciprocable needle bar in said needle head carrying a needle at its lower end, a rock frame pivotally mounted in said needle head and provided with bearings for guiding said needle bar as it'is'reciprocated, said rock frame being arranged for swinging movement in a substantially vertical plane transverse to the direction of feed of the work, connections from said shaft within said hollow frame for reciprocating said needle'bar and for swinging said rock frame, said connections serving to reciprocate said needle bar a plurality of times as'said rock frame is swung through one cycle of its swinging movement, said connections including a vertically disposed shaft in said standard and a cam secured to said vertically disposed shaft for positively swinging said r'ock frame back and forth, an oscillatable looper in said base cooperating with said needle in the formation of stitches, and connections from said drive shaft within said hollow frame for imparting loop seizing and'shedding movements to said looper upon each revolution of said shaft and for shifting the zone of loop seizing and shedding movements of said looper in coordination with the swinging movements of said-rock frame, said last mentioned connections being disposed in substantially the same vertical plane as said first menti'oned connections and including means carried by said vertically disposed shaft for shifting said zone of loop seizing and shedding movements of said looper.

3. A'sewing machine adapted to provide a zigzag line of stitching which comprises a hollow frame having a work supporting base, a vertical standard and an overhanging arm carrying a needle head, a main drive shaft journaled in said frame, means driven by saidshaft for advancing work across said base, a reciprocable needle bar in said needle head carrying a needle at its lower end, a rock frame pivotally mounted in said needle head and provided with bearings for guiding said needle bar as itis reciprocated, said rock frame being arranged for swinging movement in a plane transverse to the direction of feed of the work, connections from said shaft with* in said hollow frame for reciprocating said needle bar and for swinging said rock frame, said connections serving to reciprocate said needle bara plurality of times as said rock frame is swung through one cycle of its swinging movement, said connections including a vertically disposed shaft in said standard, a disk carried by said vertically disposed shaft adjacent its upper end, said disk having complementary cam formations projecting from its faces, a rock member pivotally mounted in said frame 1 0 and carrying a pair of rollers each cooperati'ng wi'thone of the faces of said-disk for positive-movement? ofa'said .member in 'bothdirections, and means; connectingsaid rock member with said rock frame for swing'ingfth'e latter, an oscillatable looper in said base cooperatingrwith said needle in the formation of stitches, and connections from said drive shaft within said hollow frame for imparting loop seizing and shedding movements and needle avoidmovements to said looper upon each revolution of said shaft and for shifting the zone ofloop seizing and shedding movementsof said looper in' coordination'with the swinging movements of said rock frame, said last mentioned connections including means carried by said vertically disposed shaft for shifting said zone of loop seizing and'shedding movements of said looper.

4. A sewing machine adapted to provide a zigzag line of stitching which comprises a hollow frame having. a work supporting base, a vertical standard and an overhanging arm carrying a needle head, a main drive. shaft journaled in said frame, means 'driven by said shaft for advancing work across said base, a reciprocable needle-bar in said needle head carrying a needle at its lower end, a rock frame pivotally mounted in said needle he'ad' and provided with bearings for guiding said needle bar as it is reciprocated, said rock frame being arranged for swinging movement in a plane transverseto the di- 'rection of feed of the'work, connections from said shaft within said hollow frame for reciprocating said needlebar and for swingingsaid rock frame, said connections serving to reciprocate said needle bar a plurality oftimes as said rock frame" is swung through one cycle of its swinging movement, said connections including a vertically disposed shaft in said standard, a disk carried by said vertically disposed shaft adjacent its upper end,.said disk having complementary cam formations projecting from its faces, said cam formations involving a plurality of rising and descending surfaces and a plurality of intermediate flat surfaces providing a' series of dwells, a rock member pivotally mounted in said frame carrying a pair of rollers each cooperating with one of the faces of said disk for positive movement of said member in both directions, and means connecting said rock member with said rock frame for swinging the latter, an oscillatable looper in said base cooperating with said needle in the formation of stitches, and connections from said drive shaft within said hollow frame for imparting loop seizing and shedding movements and needle avoid movements to said looper upon each revolution of said shaft and for shifting the zone of loop seizing and shedding movements of said looper in coordination with the swinging movements of said rock frame, said last mentioned connections including an eccentric carried by said vertically disposed shaft for shifting said zone of loop seizing and shedding movements of said looper.

5. A sewing machine adapted to provide a zigzag line of stitching which comprises a hollow frame having. a work supporting base, a vertical standard and an overhanging arm carrying a needle head, a main drive shaft journaled in said frame, means driven by said shaft for advancing work across said base, a reciprocable needle bar in said needle head carrying aneedle at its lower end, a rock frame pivotally mounted in said needle head and provided with bearings for guiding said needle bar as it is reciprocated, said rock frame being arranged for swinging movement in a plane transverse to the direction of feed of the work, connections from said shaft'within said hollow frame for reciprocating said needle bar and for swinging said rock frame, said connections serving to reciprocate said needle bar a plurality of times as said rock frame is swung through one cycle of its swinging movement, said connections including a vertically disposed shaft in said standard, a readily accessible and' replaceable disk carried by said vertically disposed shaft adjacent its upper end, said .disk having complementary cam formations projecting from its faces, said-cam fortnal f 'tions involving a plurality of rising and descending surfaces and a pluralityof intermediate flat surfaces, providing a series of dwells, a rock member pivotally mounted in said frame carrying a pair ofrollers each cooperating with one of the faces of said disk for positive movement of said member in both directions, and means connecting said rock member with said rock frame for swinging the latter, an oscillatable looper in said base cooperating withJsaid needle in theformation of stitches, and connections from said drive shaft within said hollow frame for imparting loop seizing and shedding movements and needle avoid movements to said looper upon each revolution of said shaftand for shifting the zone of loop seizing and shedding movements of said looper in coordination with the swinging movements of said rock frame, said last mentioned connections including an eccentric carried by said vertically disposed shaft for shift ing said zone of loop seizing and shedding movements of said looper.

6. A sewing machine adapted to provide a zigzag line of stitching which comprises a hollow frame having a work supporting base, a vertical standard and an overhanging arm carrying a needle head, a main drive shaft journaled in said frame, means driven by said shaft for advancing work acrosssaid base, a reciprocable needle bar'in said needle head carrying a needle at its lower end, a rock frame pivotally mounted in said needle head and provided with bearings for guiding said needle bar as it is reciprocated, said rock frame being arranged for swinging movement in a plane transverse to the'direction of feed of the work, connections from said shaft within said hollow frame for reciprocating said needle tbarand for swinging said rock frame, said connections serving to reciprocate said needle bar a pluralityiofttimesas said rock frame is swung through one cycle of its swinging movement, an oscillatable looper in said base cooperating with said needle in the formation of stitches, a pivotally mounted member carrying said looper, a rockable member on which said pivotally mounted member is pivoted, said rockable member being shiftable bodily int a'direction transverse to the line of feed, and connections within said hollow frame from said drive shaft for imparting pivotal movement to said pivotally mounted member to provide loop seizing and shedding movements of said looper and for imparting rocking movements to said rockable member to provide needle avoid movements of said looper, said connections including an arm extending laterally from said pivotally mounted member, a cooperating rock arm extending in the opposite direction to that of the laterally extending arm and spaced from the latter in substantially the same vertical plane as the latter and a substantially vertical link connecting the ends of said arms, and connections within said frame from said drive shaft to said rockable member for shifting the same bodily in coordination with the swinging movements: of said needle bar carrying rock frame. 7. A sewing machine adapted to provide a zigzag lin of stitching which comprises a hollow frame having a worksupporting base, a vertical standard and an overhanging arm carrying aneedle head, a main drive shaft journaled in said frame, means driven by said shaft for advancing work across said base, a reciprocable needle bar in said needle head carrying a needle at its lower end, a rock frame pivotally mounted in said needle head and provided with bearings for guiding said needle bar as it is reciprocated, said rock frame being arranged for swinging movementin a plane transverse to the direction of feed of the work, connections from said shaft within said hollow framewfor reciprocating said needle bar and for swinging said rock frame, said connections serving to reciprocate said needle bar a plurality of times as said rock frame is swung through one cycle of its swinging movement, an oscillatable looper insaid base cooperating with said ,needlein the formation of stitches, means for supporting and operating said looper comprising a rock shaft in said base extending transversely of the line of feed, a member pivotally connected at one end with said rock shaft and carrying said looper at its other end, and connections withinsaid frame from said drive shaft to said member and to said rock shaft for moving said member about its pivot to provide loop seizing and shedding bar in said needle headtcarrying a needle at its lower end,

a rock frame pivotally mounted in said needle head and provided with bearings for guiding said needle bar as it is reciprocated, said rock. frame being arranged for swinging movement in a plane transverse to the direction of feed of the work, connections from said shaft within said hollow frame for reciprocating said needle bar and for swinging said rock frame, said connections serving to reciprocate said needle bar a plurality of times as said rock frame is swung through one cycle of its swinging movement, an oscillatable looper in said base cooperating with said needle in the formation of stitches, means for supporting and moving said looper comprising a rockable member in said base and a two-part member having one of its parts pivotally connected with said rockable member, the other of said parts carrying said looper, the two parts of said member being pivotally interconnected, means for releasably holding said parts in predetermined relation to each other, said parts being shiftable relative to each other about said pivotal connection upon release of said releasable means to render said looper more accessible for threading, said rockable member being shiftable bodily in a direction transverse to the line of feed, and connections within said hollow frame from said drive shaft for imparting pivotal movement to said two-part member and rocking and bodily movements to said rock member, said bodily movements being coordinated with the swinging movements of said needle bar carrying rock frame.

9. A sewing machine adapted to provide a plurality of zigzag lines of stitching which comprises a hollow frame having a work supporting base, a vertical standard and an overhanging arm carrying a needle head, a main drive shaft journaled in said frame, means driven by said shaft for advancing work across said base, a reciprocable needle bar in said needle head carrying a plurality of needles at its lower end, a rock frame pivotally mounted in said needle head and provided with bearings for guiding said needle bar as it is reciprocated, said rock frame being arranged for swinging movementin a substantially vertical plane transverse to'the direction of feed of the work, connections from said shaft within said hollow frame for reciprocating said needle bar and for swinging said rock frame, said connections serving to reciprocate said needle bar a plurality of times as said rock frame is swung through one cycle of its swinging movement, a plurality of oscillatable loopers in said base cooperating with said needles in the formation of stitches, and connections from said shaft within said hollow frame for imparting loop seizing and shedding movements and needle avoid movements to said loopers upon each revolution of said shaft and for shifting the zone of loop seizing and shedding movements of said loopers in coordination with the swinging movements of said rock frame.

10. A sewing machine adapted to provide a plurality of zigzag lines of stitching which comprises a hollow frame having a work supporting base, a vertical standard, and an overhanging arm carrying a needle head, a main drive shaft journaled in said frame, means driven by said work, connections from said shaft within said hollow frame for reciprocating said needle bar and for swinging said rock frame, said connections serving to reciprocate said needle bar a plurality of times as said rock frame is swung through one cycle of its swinging movement, a plurality of .oscillatable loopers in said base cooperating with said needles in the formation of stitches, and connections from said shaft within said hollow frame for imparting loop seizing and shedding movements and needle avoid movements to said loopers upon each revolution of said shaft and for shifting the zone of loop seizing and shedding movements of said loopers in coordination with the swinging movements of said rock frame, said needles and loopers being so positioned in relation to each other and to the extent of movement of said needles transverse to the line of feed as tocause said lines of zigzag stitching to overlap and interlock with each other at periodic intervals.

11. A sewing machine adapted to provide a zig zag-line of stitching which comprises a hollow frame having a work supporting base, a vertical standard and an overhanging arm carrying a needle head, a main drive shaft journaled in said frame, means driven by said shaft for advancing work across said base, a reciprocable needle bar in saidneedle head carrying a needle at its lower end, a rock frame pivotally mounted in said needle head and provided with bearings for guiding said needle bar as it is reciprocated, said rock frame being arranged for swing- 7 ing movement in a substantially vertical plane transverse to the direction of feed of the work, connections from said shaft within said hollow frame for reciprocating said needle bar and for swinging said rock frame, said connections serving to reciprocate said needle bar a plurality of times as said rock frame is swung through one cycle of its swinging movement, an oscillatable looper in said base cooperating with said needle in the formation of stitches, means for supporting and operating said looper comprising a rock shaft in said base extending transversely of the line of feed, a member pivotally connected at one end I with said rock shaft and carrying said looper at its other end, and connections within said frame from said drive shaft to said member and to said rock shaft for moving said member about its pivot to provide loop seizing and shedding movements of said looper, for rocking said shaft to impart needle avoid movements of said looper and for shifting said rock shaft axially in coordination with the swinging of said needle bar carrying rock frame, said connections including an arm secured to said rock shaft, an eccentric on said drive shaft for rocking said arm and said rock shaft, a control shaft at right angles tosaid drive shaft and connected therewith for rotation at a slower angular speed, an eccentric on said control shaft, and means interconnecting said eccentric on said control shaft with said arm on said rock shaft for shifting the latter axially.

References Cited in the file of this patent UNITED STATES PATENTS 710,696 Klemm Oct. 7, 1902 769,039 Abercrombie Aug. 30, 1904 929,119 Bulasky July 27, 1909 1,403,093 Moffatt et al Jan. 10, 1922 1,503,921 Sharaf Aug. 5, 1924 1,738,559 Bowman Dec. 10, 1929 2,209,338 Kessler 'July 30, 1940 2,250,696 Avis July 29, 1941 2,337,119 Lutz Dec. 21, 1943 2,682,845 Casas Robert et a1. July 6, 1945 V FOREIGN PATENTS 382,938 Germany Oct. 8, 1923 

